<template>
  <el-container class="home-container">
    <!-- 头部区域 -->
    <el-header>
      <div>
        <img src="../assets/heima.png" alt="" />
        <span>权限认证管理系统</span>
      </div>
      <el-button type="info" @click="logout">退出</el-button>
    </el-header>

    <!-- 页面主体区域 -->
    <el-container>
      <!-- 侧边栏 -->
      <el-aside :width="isCollapse?'64px':'200px'">
        <!-- 折叠按钮 -->
        <div class="toggle-button" @click="toggleCollapse()">|||</div>
        <!-- 侧边栏菜单区域 -->
        <!--unique-opened 是否只保持一个子菜单的展开
           collapse  是否水平折叠收起菜单（仅在 mode 为 vertical 时可用）
           collapse-transition 是否开启折叠动画
           router 是否使用 vue-router 的模式，启用该模式会在激活导航时以 index 作为 path 进行路由跳转 
           default-active 当前激活菜单的 index-->
        <el-menu
          background-color="#333744"
          text-color="#fff"
          active-text-color="#409EFF"
          :unique-opened="true"
          :collapse="isCollapse"
          :collapse-transition="false"
          :router = "true"
          :default-active="activePath"
        >
          <!-- 一级菜单 -->
          <!-- index是当下拉菜单只有相同的index才会下拉，所以每一个一级菜单得到index要不一样 -->
          <!-- index只接受字符串， 数值+ ''字符串 = 字符串 -->
          <el-submenu :index="item.id + ''" v-for="item in menulist" :key="item.id">
            <!-- 一级菜单的模板区域 -->
            <template slot="title">
              <!-- 图标 -->
              <i :class="iconsObj[item.id]"></i>
              <!-- 文本 -->
              <span>{{item.authName}}</span>
            </template>
            <!-- 二级菜单 -->
            <el-menu-item :index="'/'+subItem.path" v-for="subItem in item.children" :key="subItem.id" @click="saveNavState('/'+subItem.path)">
              <!-- 二级菜单的模板区域 -->
              <template slot="title">
                <!-- 图标 -->
                <i class="el-icon-menu"></i>
                <!-- 文本 -->
                <span>{{subItem.authName}}</span>
              </template>
            </el-menu-item>
          </el-submenu>
        </el-menu>
      </el-aside>
      <!-- 右侧内容主体 -->
      <el-main>
        <!-- 路由占位符 -->
        <router-view></router-view>
      </el-main>
    </el-container>
  </el-container>
</template>

<script>
export default {
  data () {
    return {
      //左侧菜单数据
      menulist: [],
      //定义每个一级菜单的图标
      iconsObj:{
        '125':'iconfont icon-user',
        '103':'iconfont icon-tijikongjian',
        '101':'iconfont icon-shangpin',
        '102':'iconfont icon-danju',
        '145':'iconfont icon-baobiao'
      },
      //是否折叠侧边栏
      isCollapse: false,
      //被激活的链接地址
      activePath: ''
    }
  },

  created () {
    //获取菜单
    this.getMenuList()
    this.activePath =window.sessionStorage.getItem('activePath')
  },


  methods: {
    //退出登录
    logout() {
      //清除token
      window.sessionStorage.clear()
      //跳转登录页面
      this.$router.push('/login')
    },
    //获取所有的菜单
    async getMenuList(){
      //获取返回值的中data数据
      const{data: res} = await this.$http.get('menus')
      if(res.meta.status != 200) return this.$message.error(res.meta.msg)
      this.menulist =res.data
      // console.log(res)
    },
    //点击按钮，切换菜单的折叠与展开
    toggleCollapse(){
      this.isCollapse = !this.isCollapse
    },
    //保存链接的激活状态 
    saveNavState(activePath){
      window.sessionStorage.setItem('activePath',activePath)
      this.activePath = activePath
    }
  },
}
</script>

<style lang="less" scoped>
.home-container {
  height: 100%;
}
.el-header {
  background-color: #373d41;
  display: flex;
  justify-content: space-between;
  padding-left: 0;
  align-items: center;
  color: #fff;
  font-size: 20px;
  > div {
    display: flex;
    align-items: center;
    span {
      margin-left: 15px;
    }
  }
}

.el-aside {
  background-color: #373d41;
  .el-menu{
    border-right: none;
  }
}

.el-main {
  background-color: #eaedf1;
}

.iconfont {
  margin-right: 10px;
}
.toggle-button {
  background-color: #4A5064;
  font-size: 10px;
  line-height: 24px;
  color: #fff;
  text-align: center;
  //字体间距增大
  letter-spacing: 0.2em;
  //鼠标放上去变为小手
  cursor: pointer;
}
</style>